Clockwork Behemoth

Magic Resistance. The clockwork behemoth has advantage on saving throws against spells and other magical effects.

Immutable Form. The clockwork behemoth is immune to any spell or effect that would alter its form.

Slam. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 42 (6d10 + 10) bludgeoning damage.

 Explosive Blast (Recharge 5-6). The clockwork behemoth releases a massive burst of arcane energy in a 60-foot radius around itself. Each creature in the area must make a DC 22 Dexterity saving throw, taking 88 (16d10) force damage on a failed save, or half as much damage on a successful one.

The clockwork behemoth can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The clockwork behemoth regains spent legendary actions at the start of its turn.

Slam Attack. The clockwork behemoth makes one slam attack.

Arcane Charge (Costs 2 Actions). The clockwork behemoth charges forward in a straight line up to its speed and slams into a creature or object, dealing 28 (4d10 + 10) bludgeoning damage and pushing the target up to 20 feet away from the behemoth.

Explosive Leap (Costs 3 Actions). The clockwork behemoth leaps into the air, releasing a massive burst of arcane energy in a 60-foot radius around itself. Each creature in the area must make a DC 22 Dexterity saving throw, taking 88 (16d10) force damage on a failed save, or half as much damage on a successful one. The behemoth lands in an unoccupied space within 30 feet of its starting point.